> Thinking about it more, it might be cleaner to just make the extended> mode a flag, e.g.,> dret = radeon_ddc_probe_extended(radeon_connector,> radeon_connector->requires_extended_probe);> and handle the extended fetch in the same probe function.>

OK. That makes also sense. I will adapt again the patch.

> > + /* RS690 HDMI DDC quirk:> > + * Some integrated ATI Radeon chipset implementations (e. g.> > + * Asus M2A-VM HDMI) indicate the availability of a DDC even> > + * when there's no monitor connected to HDMI. For HDMI> > + * connectors we check for the availability of EDID with> > + * at least a correct EDID header and EDID version/revision> > + * information. Only then, DDC is assumed to be available.> > + * This prevents drm_get_edid() and drm_edid_block_valid() of> > + * periodically dumping data and kernel errors into the logs> > + * and onto the terminal, which would lead to an unacceptable> > + * system behaviour */> > + if (connector_type == DRM_MODE_CONNECTOR_HDMIA &&> > + (rdev->family == CHIP_RS690 ||> > + rdev->family == CHIP_RS740 ||> > + rdev->family == CHIP_RV630))> This seems like an arbitrary selection of chips. I haven't heard of> any problems related to ddc on rv630. Also I think we should limit it> to the specific connector that is problematic rather than all hdmi> ports. In the case of your board, it seems the hdmi port on the> add-in card is the only problematic one. Lots of rs690 motherboards> have hdmi ports on the motherboard itself that work fine. I'd prefer> to match based on the pci device and subsytem ids and the> supported_device and connector type. See radeon_atom_apply_quirks()> in radeon_atombios.c for an example. Something like:> > radeon_connector->requires_extended_probe => radeon_connector_needs_extended_probe(rdev, supported_dev,> connector_type);

I've added RS740 because linux uses the same firmware and this chip wasalso part of the other patch you mentioned in your first e-mail. RV630was added because I checked freedesktop bug 31943. The problem describedthere is different from the one here, but I saw logs, when no monitorwas connected, and for this situation the patch would help.

I felt rather safe with the above approach, as nothing will go wrong, ifwe check the HDMIA type connectors also RS690 of another manufacturers.We just check for a valid first six bytes set of the EDID header now.